/* let a;
let b;
a=b=1;
console.log(a,b);
a=2;
b=2;
console.log(a,b);

let c=d=3;
console.log(c,d);

 */
var a = {age: 11}
var b = 12;
a.x = b = 'tom';
console.log(a,b);
//正常从右往左执行   但是a.x的优先级要比 b = 'tom'的优先级高 